Observer-based H∞ fault-tolerant attitude control for satellite with actuator and sensor faults

Abstract

This paper investigates the fault-tolerant attitude stabilization control problem for the satellite system subject to actuator failures, sensor failures and external disturbances. First, the H∞ observer is designed to estimate both system states and faults simultaneously. In order to reduce the effect of faults or failures, an auxiliary observer is introduced to improve the observation precision. Exploiting a novel auxiliary variable, the unavailable term in auxiliary observer is eliminated and the real observer is achieved. Second, the observer-based output feedback fault-tolerant control scheme is proposed for the satellite systems to handle actuator and sensor faults, which can stabilize the attitude angle and angular velocity with high precision. Finally, the effectiveness of proposed method is demonstrated via the simulation experiments.